Burglar-alarm



. 1. MILLER. BURGLAR ALARM. APPLICATION FILED DEC.27, l9I9.

Patented Mar. 8, 1921.

a m M UNITED STATES JOHN MILLER, 01? RAN'IOUL, ILLINOIS.

BURGLAR-ALARM.

Specification of Letters Patent.

Patented Mar. 8, 1921.

Application filed December 27, 1919. Serial No. 347,647.

T all whom it may concern:

Be it known that I, JOHN MILLER, a citizen of the United States, residing at Ran toul, in the State of Illinois, have invented new and useful Improvements in Burglar- Alarms, of which the following is a specification.

This invention relates to burglar alarms and has for its primary object the construcion of a simple, inexpensive device of few parts capable of giving alarm by firing a cartridge.

An object of the invention is the arrange ment of parts whereby the tension of the spring may be regulated at will and besides the movable element of the alarm may as sume a plurality of positions so as to readily adapt itself to various purposes.

With these and other objects in view the invention will be better understood from the following detailed description taken in connection with the accompanying drawing wherein- Figure 1 is a side elevation of the alarm.

Fig. 2. is a vertical sectional view.

Fig. 3 is a horizontal sectional view.

Fig. 4 is a sectional View through a portion of the rod or plunger.

Figs. 5 and 6 are detailed views of a sli htly modified form of my invention.

gain referring to the drawings illustrating two forms in which my invention may be constructed #1 designates a plate for connection to a window frame or door frame so that the plunger 2 supported thereby may be moved in the opening or closing of a window or door. The plunger 2 is in the form of an inverted L shaped rod, the short limb 3 of which is arranged in engagement with the window or door while the long limb 4 is slidably mounted in the bearings 5. Encircling the limb 4. is a coil spring 6 resting upon a pin 7 which, if found advantageous in practice, may be adjustably arranged in the openings 8 in the rod so as to regulate the pressure of the spring. The pin 7 is adapted to be arranged upon either of the two pins 9 projecting from the plate so as to compress the spring and further allow the position of the arm 3 to be changed. The lower portion of the plate is formed into a cartridge holder 10 shown supporting a cartridge 11. From this construction it will be seen that when the window or door is opened the rod will be slightly rotated which will dislocate the pin 7 from the pin 9 and allow the spring 6 to expand for forcibly moving the end of the rod into enga ement with the cap of the cartridge for ring same.

In Figs. 5 and 6 I have shown a slight modification of my invention so as to increase my protection as I wish to be understood that my invention may be constructed in various other manners than shown in Figs. 1 to 1 inclusive. In this particular case I have shown pin 7 in the form of a projection 12 on a sleeve 13 slidably mounted on the rod and clamped in an adjustable position by the screw 14, thus I am able to regulate the tension of the spring and besides to change the angular position of the projection 12 relative to the pins 15 so that the short arm 3 may be arranged in a plurality of positions in practice. Referring to Fig. 6 it will be seen that a portion of each pin 15 is curved as illustrated at 16 so as to allow the proper association of the projection and pin when the short arm 3 is arranged at a plurality of angles.

It is, of course, to be understood that the invention may be constructed in various other manners and the parts associated in different relations andtherefore I do not desire to be limited in any manner except as set forth in the claims hereunto appended.

Having thus described my invention what I claim is- 1. A burglar alarm comprising a plate having a portion formed into a cartridge holder, a plunger supported by the plate for movement into engagement with the cartridge, a. spring for forcing the plunger into engagement with the cartridge, a pair of pins projecting from the plate and a sleeve adjustably mounted on the plunger and acting against said spring and further having a projection adapted to engage either of said pins for compression of the spring.

2. A burglar alarm comprising a plate having a portion formed into a cartridge holder, a plunger supported by the plate for movement into engagement with the cartridge, a spring for forcing the plunger into engagement with the cartridge, a pair of pins projecting from the plate, a sleeve adjustably mounted on the plunger and acting against said spring and further having a projection adapted to engage either of said pins for compression of the spring, each said pins having a portion curved in a direction to allow the plunger to assume a plurality of positions without disturbing engagement opposite sides of the plunger and having between the projection and a'pin. their end portions curved concentrically of 10 3. A burglar alarm comprising a plate the axis ofitheplun'ger, and a sleeve adjusthaving a portion formed into a cartridge ably mounted on the plunger and having a 5 holder, a plunger supported by the plate for projection adapted to rest upon said pins.

engagement with the cartridge, a spring for In t stimony whereof I afiiX my Signature. forcing the plunger intov engagement'with the cartridge, a pair of pins arranged upon JOHN MILLER. 

